Confessions of Adopted

Jeremy Manker has a half-Cherokee father and an Italian American mother. As a child he lived in Korea for years as the son of an Army doctor. His mother taught English while his father works at the US Army hospital in Seoul. In high school he begins to get a strange feeling that he may be an adopted son in spite of his birth certificate that says he is born in the US Army hospital in Seoul. Although it torments him, he can't raise the issue with his parents for he is fearful they will consider their only son to be ungrateful.
When he is at a college, however, his parents revealed to him that he is adopted in Korea. In fact, he is a half Korean not a Cherokee. They tell their son how they tried long and hard to locate his birth parents to no avail. They implore their son to find his birth parents as their last wishes.
How can he find his parents who disappeared after leaving their infant son at the police station 45 year ago? They have not ever contacted the orphanage, from which Jeremy is adopted.